Once the host of major tennis tournaments and concerts, the West Side Tennis Club in Forest Hills will welcome its biggest event in more than two decades on Aug. 28, when Mumford and Sons performs.

What’s old has become new again. On Aug. 28, more than 17,000 people will fill the West Side Tennis Club in Forest Hills, Queens to see Mumford and Sons, the first major event the venue has hosted in more than 25 years.

Built in 1921, the arena was once the region’s home for tennis, hosting the U.S. Open from 1924 to 1977, the Davis Cup final 10 times — more than any other venue — and the Tournament of Champions three times.

The Beatles, Bob Dylan, The Rolling Stones, The Who, Frank Sinatra and Jimi Hendrix have also graced the arena’s stage.

But after losing the U.S. Open to Flushing Meadows, revenue went with it, and eventually, the arena stopped hosting concerts and major events altogether. “Over the past eight to 10 years, the stadium has been dormant,” said Roland Meier, the club’s president.

After a 2009 proposal to renovate the stadium into condominiums was voted down by club members, Meier, who is serving his second term, decided it was time to take action.

Club officials launched a marketing campaign, including television commercials, which eventually caught the attention of Mike Luba of S2BN Entertainment, who brought the members of the English folk band to tour the arena. “I was told that when Mumford and Sons were shown the place, they fell in love with it,” Meier said.

Mumford and Sons’ latest album, “Babel,” won Album of the Year at the 2013 Grammy Awards. “Oh, it’s big,” Meier said. “The whole neighborhood is talking about it.”

Millions of dollars have already been put into arena renovations, which include the removal of benches and power washing of its bowl. Though the stadium’s infrastructure was sound, Meier said there was water seepage and deterioration, which has since been fixed and approved by engineers.

Profits from the concert will be put towards future renovations, which Meier said he hopes will lead to more shows. But his biggest desire, he said, is to bring the stadium back to its tennis glory. He acknowledged their inability to compete with Flushing Meadows, but hopes to host smaller tournaments and exhibition matches.

The arena is conveniently located, adjacent to the Forest Hills Long Island Railroad train station, and is a less than 10-minute ride from Jamaica.

Meier noted that any future development is contingent on the concert’s success, but said he remains optimistic. And after years of dormancy, he views the arrival of one the world’s biggest acts as more than just a one-night show. “Mumford and Sons represents for us an opportunity,” Meier said. “We haven’t had a sold-out concert for 25 years. And all of a sudden you have this … it’s certainly a transformation.”